Question: A large cheese pizza costs $\$18$. Each topping you add on costs $\$1.50$. How much would it cost to get a large cheese pizza with $c$ toppings added? Write your answer as an expression. $\$$
Answer: Let's see what happens as the number of toppings increases: Number of toppings Cost of pizza ${0}$ $18 + 1.5 \cdot {0} = 18$ ${1}$ $18 + 1.5 \cdot {1} = 19.5$ ${2}$ $18 + 1.5 \cdot {2} = 21$ Number of toppings Cost of pizza ${c}$ $18 + 1.5\cdot {c} = 18 + 1.5c$ The answer: $18+1.5c$